1. Field of the Invention
The present invention relates to a rotary adsorption/desorption type gas treating apparatus for eliminating a target substance from treatment subject gas containing the substance by adsorbing the substance and then desorbing the same. The apparatus is used, for instance, for separating and eliminating a paint solvent from atmosphere containing the solvent exhausted from a painting factory.
2. Description of the Related Art
FIGS. 8 and 9 show a known apparatus of the above-described type. As shown, this apparatus includes a rotary drum 1' rotatable about a pivotal axis P and having a plurality of gas-passage compartments 4' arranged side by side along the peripheral direction of the drum and defines, in the peripheral direction, an adsorption zone X' for allowing passage of treatment subject gas G through the compartment(s) 4' in the radial direction of the drum and a desorption zone Y' for allowing passage of refreshing gas H through the compartment(s) 4' in the generally opposite radial direction. At each gas-passage compartment 4', there is provided a gas-permeable adsorbing element 7', in the form of a flat plate element, with an inclination relative to the radial direction of the drum.
In operation, in accordance with rotation of the rotary drum 1', the respective compartments 4' are alternately brought into registered relationship with the adsorption zone X' and the desorption zone Y'. In the adsorption zone X', as the subject gas is passed through the adsorbing element 7', the target substance contained in the gas is adsorbed on the adsorbing element 7'. Then, in the desorption zone Y', the substance on the element 7' is desorbed to the refreshing gas H, such that the element 7' becomes refreshed to be ready for a next adsorption/desorption cycle. In this manner, the apparatus can treat the subject gas G continuously.
Further, each gas-passage compartment 4' includes a partition wall 3' which serves to separate this compartment 4' from another compartment adjacent thereto. In operation, when the compartment 4' is placed between the adsorption zone X' and the desorption zone Y', the partition wall 3' serves as an inter-compartment partition for partitioning between the adsorption zone X' and the desorption zone Y' in order to prevent gas leakage therebetween.
According to the above-described conventional construction, the adsorbing element 7' in the form of a flat plate is disposed with an inclination relative to the radius of the rotary drum 1', thereby to reduce the diameter of the drum 1' while maximizing the gas passage area of the adsorbing element 7'. However, since the subject gas or refreshing gas is caused to pass the adsorption zone X' or the desorption zone Y' along the radial direction of the rotary drum, it has been necessary to form, at the center portion of the rotary drum 1', an outlet passage 12' for the subject gas G' after adsorption treatment and an inlet passage 13' for the refreshing gas H before desorption treatment, or an inlet passage 11' for the subject gas G before the adsorption treatment and an outlet passage 14' for the refreshing gas H' after the desorption treatment each with a passage sectional area commensurate with an amount of the gas to be passed therethrough. This imposes limit on the reduction of the diameter of the rotary drum 1' and consequently on the compactness of the entire apparatus.